Rocket-propelled cluster weapon

ABSTRACT

A warhead for an aerial missile containing a plurality of submissiles. The warhead is provided with an inertia responsive mass which in response to acceleration forces overcomes the forward urging of spring to maintain a pair of normally outwardly urged detents seated in the annular groove on a centrally disposed axial shaft thereby to maintain the slideable warhead nose forwardly urged to seal the warhead against admission of ram air pressure into the warhead cavity. Upon deceleration, the spring urges the inertia mass forwardly enabling the detents to unseat and the warhead nose to slide rearwardly thereby permitting admission of ram air pressure into the warhead cavity which affects rupture of the warhead fairing and release of the submissiles along an intercept path to the target.

'ilnited States Patent Luttrell et al.

Sept. 9, 1975 ROCKET-PROPELLED CLUSTER WEAPON Primary Exam'inerVerlin R.Pendegrass Attorney, Agent, or FirmR. S. Sciascia; J. A. Cooke 57ABSTRACT A warhead for an aerial missile containing a plurality ofsubmissiles. The warhead is provided with an inertia responsive masswhich in response to acceleration forces overcomes the forward urging ofspring to maintain a pair of normally outwardly urged detents seated inthe annular groove on a centrally disposed axial shaft thereby tomaintain the slideable warhead nose forwardly urged to seal the warheadagainst admission of ram air pressure into the warhead cavity. Upondeceleration, the spring urges the inertia mass forwardly enabling thedetents to unseat and the warhead nose to slide rearwardly therebypermitting admission of ram air pressure into the warhead cavity whichaffects rupture of the warhead fairing and release of the submissilesalong an intercept path to the target.

12 Claims, 1 Drawing Figure PATENTEDSEP :915

John L. Luhrell William E. Preston William 8. Richardson INVENTORS.

MN Wm ATTORNEYS.

ROCKET-PROPELLED CLUSTER WEAPON The invention described herein may bemanufactured and used by or for the Government of the United States ofAmerica for governmental purposes without the payment of any royaltiesthereon or therefor.

The present invention relates to warheads and more particularly to awarhead for a rocket or missile containing a cluster of submissileswhich are released from the warhead at the time of burnout of the rocketpropellant for impact with the target.

It has long been the practice to employ multiparticle warheads forprojectiles or rockets, the particles being formed by fragmentation ofthe warhead casing upon the detonation of an explosive charge within thewarhead. Although such warheads work satisfactorily under mostconditions, the full potential of the warhead is not utilized becausethe size of the particles produced by the fragmentation of the warheadis unpredictable and is at best difficult to control by scoring of thewarhead casing. In the conventional warheads, the fragments from thewarhead casing produced upon detonation of the explosive charge areusually projected in all directions in a random manner, thus producingthe situation that the particular particles which hit the target maystrike the target at a tangential angle and therefore do not inflicttheir full damage upon the target.

The general purpose of this invention is to provide a warhead for arocket which embraces all of the advantages of similarly employedwarheads and possesses none of the aforedescribed disadvantages. Toattain this objective, the warhead of the present invention contains acluster of submissiles having flight stabilizing fins thereon and beingpositioned within a warhead fairing which is caused to open upon theburnout of the rocket propellant whereby the rocket and fairingdecelerate and permit the submissiles to continue their travel towardthe target at hypervelocity speeds. Upon release from the fairing, theflight stabilized submissiles travel in an intercept path with thetarget along slightly diverging paths to produce a shotgun-like patternto as sure impact with the target by one or more of the submissiles atan angle substantially normal to the target, thus enabling thesubmissile to inflict its maximum destructive capability.

It is an object of this invention to provide a simple and reliable yethighly effective weapon for projecting a plurality of inert projectilesat a target.

Another object of the invention is to provide a warhead for launching acluster of projectiles along an intercept path with a target athypervelocity speeds.

Another object of the invention is to provide a rocket warhead forreleasing a cluster of projectiles in such a manner that each of theprojectiles takes an intercept path with a target.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawing wherein:

The FIGURE shows a longitudinal view of the weapon with the warhead ofthe weapon shown in section.

Referring now to the drawing, there is shown a warhead adapted to beattached to the forward portion of a rocket 11 by any suitable means,the details of the rocket not being significant for the purposes of thisinvention since the warhead may be delivered by any one of a pluralityof conventional rockets. The body of the warhead is defined by asubstantially frusto-conical fairing 12 having an axial bore 13extending therethrough to receive the nose element for triggering thecluster release system. The fairing is further provided with acounterbore 14 to define a chamber for receiving a cluster of inertsubmissiles 15. Each of the submissiles is formed from an inert highdensity material and is provided with an elongated configuration havinga low aerodynamic drag and being provided with fins 16 on the tailportion thereof to stabilize the flight of the submissile during itstravel toward the target upon release from the warhead. The submissilesare packed in annular cluster around an annular submissile support block17 which is secured to a axial shaft 18 mounted upon a support base 19.The support base 19 is secured to the forward portion of a rocket motorcasing 11 by any suitable means and has formed therein slots 21 toreceive the tail fins 16 of the submissiles to hold the submissiles intheir stacked array.

The warhead is so constructed as to release the cluster of submissiles15 upon sensing the condition of deceleration caused by burnout of therocket propellant. The interior of the warhead is provided with anenlarged inner diameter portion 22 to define a cavity to receive ramairpressure after the rocket propellant has been consumed. The warheadfairing is so constructed as to be torn apart by the entrance of ram airpressure into the cavity 22 in such a manner as to provide anuninterrupted path for the submissiles as the fairing and rocket motorfurther decelerate and the submissiles are permitted to continue ontheir path toward their target. To permit an easy and effectiveseparation for removal of the fairing assembly, the fairing isconstructed of a thin metallic skin and is packed with a lightweightrigid filler material to give it regidity and strength, the metallicskin of the fairing being provided with a plurality of grooves extendingfrom the apex to the base of the frusto-conical fairing to provideweakened portions in the fairing skin. Upon entrance of the ram airpressure into the cavity 22, the ram air pressure acts upon the taperedcavity wall 24 to produce forces on the fairing in a radially outwardlydirection, thus causing the fairing to tear along the weakened groovesformed in the fairing skin and consequently be removed from itsobstructing position in the path of the submissiles. Entrance of ram airpressure into the cavity 22 is pre vented prior to propellant burnout bymeans of a cluster release assembly 23 which seals the entrance to thecavity and is withdrawn from its sealing position upon the decelerationof the warhead.

The cluster release assembly 23 has a cylindrical body portion having adiameter substantially equal to the inner diameter of the entrance tothe apex of the frusto-conical fairing. The cluster release assembly isprovided with a hemispherical end portion 25 which, when the clusterrelease assembly is in its sealing position, provides the fairing with acontinuous smooth aerodynamic surface at the forward end thereof. Thecluster release assembly is mounted upon a shaft 26 which is connectedto the base 19 by the axial shaft 18. The cluster release assembly isadapted to be moved by ram air pressure acting upon the hemisphericalsurface 25 from its sealing position shown in the drawing to an openposition rearwardly along shaft 26. The release assembly is locked inthe position shown by means of a pair of spring fingers 27 havingdetents 28 integrally formed on the ends thereof, the detents 28 beingreceived within an annular recess 29 formed in the shaft 26. The springfingers 27 are resiliently baised outwardly out of locking engagementwith the annular recess 29 but are held in the locked position by meansof a peripheral engagement with a cylindrical inertial weight 31. Theinertial Weight is mounted upon the shaft 26 for longitudinal slidingmovement thereon and is resiliently baised in a forward direction forcontact with a stop plate 32 by means of a helical compression spring 33positioned within the cylindrical release assembly. The inertial weightis held in the position shown by means of a shear pin 34 positionedwithin and extending through complimentary apertures formed in theinertial weight and the shaft 26. When the cluster release assembly isin its sealing position shown in the FIGURE, an annular flange 35mounted upon the release assembly 23 and spaced therefrom is in lockingengagement with an inwardly directed reentrant flange 36 formed at theapex of the frusto-conical fairing.

In operation, the rocket l l is aimed at the target and ignited, thesetback forces of acceleration act upon the inertial weight 31 to severthe shear pin 34 and permit the inertial weight to fully compress thehelical spring 33. During the acceleration of the rocket throughout theburning time of the rocket propellant, the inertial weight holds thehelical spring 33 in its fully compressed condition and continues tolock the detents 28 within the annular recess 29 to maintain the clusterrelease mechanism 23 in its locked sealing position. Upon theconsumption of the rocket fuel, the rocket begins to decelerate, thuscausing the inertial weight 31 to move forward under the force ofdeceleration and as assisted by the compression spring 33 so that theinertial weight reaches an abutting contact with the stop plate 32. Whenthe inertial weight is in this position, the locking detents 28 on thespring fingers 27 are permitted to be urged radially outwardly out ofengagement with the annular recess 29 in the shaft thereby freeing thecluster. release mechanism 23 for longitudinal movement along the shaft26. The ram air pressure acting upon the hemispherical end portion 25 ofthe cluster release assembly forces the cluster release assembly 23 intoabutment with annular wall 37 formed on the shaft 26. The cylindricalcluster release mechanism having been moved into contact with wall 37,the locking engagement of annular flanges 35 and 36 is uncoupled and theram air pressure is permitted to enter the cavity 22. As the ram airpressure acts upon the tapered cavity wall 24, moments of force aredeveloped perpendicular to the axis of the warhead to tear the fairing12 along its weakened groove portions and remove the fairing from thewarhead, thus further decelerating the rocket motor and warhead andpermitting the cluster of submissles 15 to continue forwardly along anintercept path toward the target. The aerodynamic pressure acting uponthe cluster of submissiles causes the submissiles to be deployed in ashotgun-like pattern while the fins 16 on the tail sections of thesubmissiles maintain the submissiles in a trajectory substantiallyidentical to that of the trajectory of the warhead prior to burnout ofthe rocket propellant.

The warhead of this invention is adapted for use with any suitablerocket motor and it has been found that known rocket motors willaccelerate the warhead through a velocity of 7,000 to 8,000 feet persecond during the propellant burning time of approximately 1 second. Byconstructing the submissiles of a high density material such as tungstenor depleted uranium and by shaping the submissiles to have a length todiameter ratio of about 5 to l, the submissiles will continue on theirintercept paths to the target at an initial velocity of about 8,000 feetper second upon release from the warhead and, due to their lowaerodynamic drag, will have very high kinetic energy and momentum uponimpact with the target. Upon striking a target, hypervelocityprojectiles do not simply perforate the target, but fragmentexplosively, thus greatly amplifying the destructive effects of theprojectiles. The launching rocket motor may be an unguided rocket, thusreducing the expense and eliminating the intricacies of the guidancecontrol system, while the design of the warhead enables the submissilesto intercept the target at angles substantially normal to the target andalso maximizes the kinetic energy and momentum of the submissiles tothereby provide a weapon having high destructive capability. When theweapon is used against ground personnel the warhead may be provided witha larger number of submissiles of smaller size than when the weapon isused against material or aerial targets. It is apparent therefore thatthe present invention provides an inexpensive weapon which is simple inconstruction and yet very reliable and having a high destructivecapability.

Obviously many modifications and variations of the present invention arepossible in light of the above teachings. It is therefore to beunderstood, that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. A missile warhead comprising a frusto-conical warhead fairing havingan axial bore extending therethrough,

a base plate adapted to be mounted upon a missle and having the base ofthe frusto-conical fairing secured thereto, said plate closing one endof said axial bore,

a support shaft mounted upon said base plate and extending into saidaxial bore,

said fairing having a counterbore formed therein adjacent said baseplate,

a plurality of submissiles positioned within said counterbore,

said fairing having an internal cavity formed therein adjacent the openend of said axial bore and being in fluid communication with said axialbore, the diameter of said cavity being greater than the diameter ofsaid bore,

submissile release assembly slideably mounted upon said shaft formovement from a first position wherein said assembly prevents air flowinto the cavity to a second position wherein said assembly permits airto fiow into said cavity, and means for locking said release assembly insaid first position and for unlocking said release assembly in responseto deceleration of the warhead for movement to said second position,

whereby ram air pressure about the warhead may enter the cavity upondeceleration of the warhead occurring at the termination of thrust by awarhead propelling motor to tear away the fairing and release thesubmissiles for a ballistic trajectory toward a target.

2. The warhead of claim 1 wherein said plurality of submissiles arepacked in an annular cluster having an inner diameter greater than thediameter of said axial bore.

3. The warhead of claim 2 wherein said submissiles are constructed of aninert high density material.

4. The warhead of claim 3 wherein said submissiles have a pointed noseportion and an elongated body portion and have fins mounted thereon tostabilize the ballistic flight of the submissiles.

5. The warhead of claim 1 wherein said fairing is constructed of amaterial which, when subjected to ram air pressure within said cavity,will tear apart and open the fairing for release of the submissiles.

6. The warhead of claim 1 wherein said fairing comprises an annular bodyhaving spaced apart walls of thin metallic material,

a mass of lightweight filler material positioned within and filling thespace between said walls.

7. The warhead of claim 6 wherein said walls have stress concentratinggrooves formed therein and extending from the apex of the fairing to thebase of the fairing.

8. The warhead of claim 1 wherein said submissile release assemblycomprises a hollow cylindrical housing coaxially mounted upon said shaftfor sliding movement thereon,

said cylindrical housing having a hemispherical end portion formedthereon,

whereby when said submissile release assembly is in said first position,the hemispherical end portion provides the fairing with a smoothaerodynamic surface.

9. The warhead of claim 8 further comprising a re-entrant annular flangeformed on said fairing adjacent said axial bore at the apex end of saidfairing, and

an annular flange formed on the outer peripheral surface of said housingand releasably interlocking said re-entrant flange when said housing isin said first position.

10. The warhead of claim 8 wherein said means for locking saidsubmissile release assembly comprises an annular inertial weightcoaxially mounted upon said shaft and being positioned within saidcylindrical housing,

a spring for resiliently biasing said weight toward the apex of saidfairing,

at least one locking detect mounted upon said housing for lockingengagement with a groove formed in said shaft,

a shear pin for releasably holding said weight in a locking positionwherein said detents are engaged by said weight and held in lockingengagement with the groove in said shaft,

whereby acceleration of the warhead by a propelling motor will sever theshear pin to permit the resilient biasing spring to move the weighttoward the apex of the fairing after termination of thrust by thepropelling motor, thus permitting the detent to be disengaged from thegroove in said shaft to free said housing for movement along the shaftand thereby permit ram air pressure to enter said cavity and remove saidfairing and release submissiles.

11. A missile warhead comprising a tapered fairing having an opening atits apex and an internal cavity formed therein a plurality ofsubmissiles positioned within said cavan elongate shaft axially securedwithin said fairing and having a groove formed therein,

an assembly slideably mounted on said shaft and having an end portion ofsubstantially the same size as said fairing opening and at least oneresiliently urged detent,

an inertia mass slideably mounted on said shaft,

resilient means normally urging said mass in a forwardly direction,

said mass moving rearwardly on said shaft in response to accelerationforces to effect seating of said detent in said groove for securing saidend portion in sealing engagement with said opening thereby preventingadmission of ram air pressure into said cavity, said mass being urgedforwardly by said resilient means in response to deceleration forces toeffect unseating of said detent and release of said assembly forrearward movement thereby unsecuring said end portion from sealingengagement with said opening and enabling admission of ram air pressureinto said cavity for rupturing of said fairing and release of saidsubmissiles.

12. A missile warhead according to claim 11 and including means formaintaining said inertia mass in an initial position on said shaft andfor affecting release of said mass for movement in response to ashearing force. l

1. A missile warhead comprising a frusto-conical warhead fairing havingan axial bore extending therethrough, a base plate adapted to be mountedupon a missle and having the base of the frusto-conical fairing securedthereto, said plate closing one end of said axial bore, a support shaftmounted upon said base plate and extending into said axial bore, saidfairing having a counterbore formed therein adjacent said base plate, aplurality of submissiles positioned within said counterbore, saidfairing having an internal cavity formed therein adjacent the open endof said axial bore and being in fluid communication with said axialbore, the diameter of said cavity being greater than the diameter ofsaid bore, a submissile release assembly slideably mounted upon saidshaft for movement from a first position wherein said assembly preventsair flow into the cavity to a second position wherein said assemblypermits air to flow into said cavity, and means for locking said releaseassembly in said first position and for unlocking said release assemblyin response to deceleration of the warhead for movement to said secondposition, whereby ram air pressure about the warhead may enter thecavity upon deceleration of the warhead occurring at the termination ofthrust by a warhead propelling motor to tear away the fairing andrelease the submissiles for a ballistic trajectory toward a target. 2.The warhead of claim 1 wherein said plurality of submissiles are packedin an annular cluster having an inner diameter greater than the diameterof said axial bore.
 3. The warhead of claim 2 wherein said submissilesare constructed of an inert high density material.
 4. The warhead ofclaim 3 wherein said submissiles have a pointed nose portion and anelongated body portion and have fins mounted thereon to stabilize theballistic flight of the submissiles.
 5. The warhead of claim 1 whereinsaid fairing is constructed of a material which, when subjected to ramair pressure within said cavity, will tear apart and open the fairingfor release of the submissiles.
 6. The warhead of claim 1 wherein saidfairinG comprises an annular body having spaced apart walls of thinmetallic material, a mass of lightweight filler material positionedwithin and filling the space between said walls.
 7. The warhead of claim6 wherein said walls have stress concentrating grooves formed thereinand extending from the apex of the fairing to the base of the fairing.8. The warhead of claim 1 wherein said submissile release assemblycomprises a hollow cylindrical housing coaxially mounted upon said shaftfor sliding movement thereon, said cylindrical housing having ahemispherical end portion formed thereon, whereby when said submissilerelease assembly is in said first position, the hemispherical endportion provides the fairing with a smooth aerodynamic surface.
 9. Thewarhead of claim 8 further comprising a re-entrant annular flange formedon said fairing adjacent said axial bore at the apex end of saidfairing, and an annular flange formed on the outer peripheral surface ofsaid housing and releasably interlocking said re-entrant flange whensaid housing is in said first position.
 10. The warhead of claim 8wherein said means for locking said submissile release assemblycomprises an annular inertial weight coaxially mounted upon said shaftand being positioned within said cylindrical housing, a spring forresiliently biasing said weight toward the apex of said fairing, atleast one locking detect mounted upon said housing for lockingengagement with a groove formed in said shaft, a shear pin forreleasably holding said weight in a locking position wherein saiddetents are engaged by said weight and held in locking engagement withthe groove in said shaft, whereby acceleration of the warhead by apropelling motor will sever the shear pin to permit the resilientbiasing spring to move the weight toward the apex of the fairing aftertermination of thrust by the propelling motor, thus permitting thedetent to be disengaged from the groove in said shaft to free saidhousing for movement along the shaft and thereby permit ram air pressureto enter said cavity and remove said fairing and release submissiles.11. A missile warhead comprising a tapered fairing having an opening atits apex and an internal cavity formed therein a plurality ofsubmissiles positioned within said cavity, an elongate shaft axiallysecured within said fairing and having a groove formed therein, anassembly slideably mounted on said shaft and having an end portion ofsubstantially the same size as said fairing opening and at least oneresiliently urged detent, an inertia mass slideably mounted on saidshaft, resilient means normally urging said mass in a forwardlydirection, said mass moving rearwardly on said shaft in response toacceleration forces to effect seating of said detent in said groove forsecuring said end portion in sealing engagement with said openingthereby preventing admission of ram air pressure into said cavity, saidmass being urged forwardly by said resilient means in response todeceleration forces to effect unseating of said detent and release ofsaid assembly for rearward movement thereby unsecuring said end portionfrom sealing engagement with said opening and enabling admission of ramair pressure into said cavity for rupturing of said fairing and releaseof said submissiles.
 12. A missile warhead according to claim 11 andincluding means for maintaining said inertia mass in an initial positionon said shaft and for affecting release of said mass for movement inresponse to a shearing force.